The Copeland Hex Pickup

The Copeland 6dc+ is an active hexaphonic pickup designed to fit in the same slot as
a normal PAF-style humbucker. Inside the body are 12 magnets, 12 coils, and 6 transistor
preamps. The bottom of the pickup is a circuit board with terminals for
+9V and Gnd inputs and six audio outputs, one for each string.

I get regular emails from people asking about this pickup, which I installed in the
Ibanez AR-250 for use with the Jazz Looping Pedalboard.
In 2002, I bought it from Rick Copeland, who used to have a web site at "tubeamps.com".
His web site disappeared sometime in 2003, and I don't know what's up with him. I hope he is
OK and still making these things because they are great; but at the moment, there doesn't
seem to be any way to get one.

Wiring Version 1.0

Despite the Copeland's unavailability, I am going to describe my wiring since it might
be helpful to those using other pickups like the OS Music Technology pickups.

I wired the guitar with a stereo output jack with one output for the guitar
effects chain and one for the bass chain. A toggle switch on the guitar controls which strings
from the hex pickup get sent to which outputs. I use the cable from my
Chapman
Stick to split the 1/4" stereo output into two mono 1/4" plugs for the pedalboard. The guitar
plug goes into the Dano tuner and the bass plug goes into the EQ before the Chili Dog octave pedal.
The toggle switch selects between three operating modes:

Six-String Bass (all 6 strings go out the bass output)

Split (top 4 strings go out the guitar output, bottom two go out the bass output)

Six-String Guitar (all 6 strings go out on guitar output)

The Copeland pickup's transistor preamps each have a series output resistor so you can
easily mix different strings just by shorting the output terminals together:

Wiring Version 2.0

There is a problem with the above approach: the signal levels change when you switch
between split mode and either of the other modes. When you short together the hex pickup outputs,
you are creating an "averaging" mixer: the shorted output gives you the average of the individual
string outputs. As a result, the more strings you add to the mixer, the lower the output level
gets. This is particularly noticeable when switching from split
mode to bass mode, where you change from average-of-two to average-of-six. The pure bass
output is so much quieter it is unusable without adding some kind of gain externally.

To get around this problem, I added additional trimpots to ground which get switched into the
circuit to lower the output level when you are in split mode. This required the use of
a 4PDT toggle switch with a connection scheme like two of the aforementioned DPDT switches:

The idea is that we want to lower the guitar output and the bass output levels when
we are in split mode, but not lower the guitar output when we're in guitar mode
or the bass output when we're in bass mode. With the 4PDT switch, we can connect
things such that the guitar-side trimpot is connected in both split mode and bass
mode (we don't mind if the guitar-side trimpot is connected in bass mode, because the guitar
output isn't connected to any pickups). Similarly, the bass-side trimpot is connected in
split mode and guitar mode:

With the trimpots, we can adjust the levels as desired. I opted to make the
guitar a little bit louder in guitar mode than in split mode, so my guitar
solos would be a bit louder than the looped bass + chords accompaniments
over which they are played.

Here are photos showing the completed wiring:

Guitar Wiring

Closeup showing trimpots glued to 4PDT toggleswitch body

The 9V battery powers the active Copeland hex pickup; power to the pickup is switched
on and off with a push-pull switch on the guitar tone pot.

I think this wiring scheme would be useful for hex pickups other than the
Copeland; basically in any case where an averaging mixer is used.

Alternatives to the Copeland Hex Pickup

OS Music Technology

Olle Svensson from OS Music Technology makes hex pickups with a hex distortion circuit built in!
I just received a custom pickup from him very similar to the Copeland, but it appears
to have better isolation between strings. I will post some pics and sound samples once I
get it mounted in a guitar for real testing.

I don't think a bridge-mounted Roland GK-2a-type hex pickup would work very well for
this application because the Chili Dog bounces octaves quite a bit if you try to drive
it from bridge pickup. I got the Copeland specifically so I could use it in the neck
position.